Environmental pollution by primary and secondary microplastics is currently recognized as a major threat to planetary health. Transferring among organisms through food webs, they accumulate in humans and other organisms resulting in detrimental effects across the biosphere. Bacteria and fungi are known to degrade petroleum hydrocarbons. Heterogeneous communities of microbial biofilms benefit from an extended genetic repertoire and consequent metabolic and survival capacity. Our previous work demonstrated high efficiency degradation of hexadecane and crude oil by naturally occurring fungal-bacterial biofilms. These studies provide a platform for investigating the use of biofilms for combating microplastic pollution in terrestrial environments. Microorganisms were isolated from a municipal landfill in Sri Lanka. Fungal–bacterial communities that appeared during screening formed a biofilm during static culture in hexadecane and crude oil at 1% as sole carbon source. Biofilm formation was confirmed by scanning electron microscopy. Degradation of alkanes in cultures was quantitatively estimated using GC-MS. In silico investigation of putative Aspergillus flavus alkane monooxygenases was carried out using the NCBI protein database and computational tools such as PSI-BLAST, SWISS MODEL and Autodock Vina. A biofilm-forming consortium comprising Bacillus cereus and A. flavus demonstrated highly efficient synergistic degradation of the alkanes in hexadecane and crude oil in liquid culture (~99% in 7 days). Several alkane monooxygenases were identified in A. flavus as distal homologs of bacterial long chain alkane monooxygenases LadA and AlmA and the short to medium alkane monooxygenase Cyp52. Our results suggest that heterogeneous microbial biofilms are promising candidates for the application of ‘green solutions’ to combating terrestrial microplastic pollution. Future directions for consideration are improvement of the bioremediation potential of (polluted) soils through inclusion of plastic degraders in the soil microbiota. Development of stable bioformulations of biofilm forming microbes is the next step. Exploitation of the identified extracellular fungal alkane monooxygenases as biocatalysts in bioremediation formulations needs to be additionally considered.